Rowbotham and Wells were beaten to the third qualifying spot by Serbia

Olympic bronze medallists Steve Rowbotham and Matthew Wells were knocked out of the World Championship semi-finals on day five in Poland.

The double scull put in a massive push at the finish but could not hold off Serbia for the third qualifying spot.

Four GB entries, including pair Andy Hodge and Peter Reed, the women's double, men's four and sculler Alan Campbell won their semi-finals.

Sculler Katherine Grainger and the women's pair also went through.

The disappointment of the day came when the men's double scull clipped a marker buoy mid-race and could not take the third qualifying spot.

Put off when Wells lost control of his blade in the incident with the buoy, the GB men's double put in a huge surge, rating up to 41 strokes per minute to regain almost a boat length and pass Serbia in the final 100m.

But they could not hold that speed and the Serbs responded well to go through behind France and Slovenia in hot, humid conditions in Poznan.

Sweep rowers Hodge and Reed were far happier after a fast start put them almost two lengths up on the field by the 500m mark.

That tactic will be crucial if they are to beat favourites Eric Murray and Hamish Bond of New Zealand in Saturday's final.

"It feels like we've made a big step," said Hodge, back in the stroke seat after an unsuccessful experiment in reversing the order saw them beaten by the Kiwis at the last two events.

"There's still more to come but we've started executing what we've been working on and it was a good race."

Great Britain's men's four, a new combination this year of Matthew Langridge, Alex Gregory, Richard Egington and Alex Partridge, will have to emulate Hodge's Beijing crew and overhaul Australia if they are to win their final.

They dominated their semi-final but Australia, using the same line-up who ended up as Olympic silver medallists after being overtaken late in Beijing, were equally impressive in the next race.

Bebington and Vernon will have to wary of Poland and the USA in the final

However, Langridge refused to think about Australia, saying: "We can only race our own race.

"We had a good first 1,000m and that allowed us to be comfortable in the second half. We haven't put together a whole race yet."

Women's double scull Annabel Vernon and Anna Bebington - both Olympic medallists last year - were pleased with victory, although Poland and the USA looked strong in the other semi-final.

Vernon said: "We're very much doing it for each other. We're really good mates and when Anna called, 'Let's go, let's go through' it just happened.

"We're pleased with the result, we're pleased with the rhythm."

Triple Olympic silver medallist Grainger was happy just to have made the final in her first year in the single scull, although she is not expected to take a medal on Saturday.

"I'm really pleased to knock off some of those names and put myself in this position," she said. "The final is a different ball game and I have 48 hours to move it on."

A medal is what I came here for and this year I've been the closest to Mahe

Alan Campbell

However, men's single sculler Campbell looks in position for his first world medal, beating Olympic silver medallist Ondrej Synek and Olympic champion Olaf Tufte - who barely took third place - for the fifth time this year.

Mahe Drysdale of New Zealand is favourite to take his fourth world title but Campbell said: "A medal is what I came here for and this year I've been the closest to Mahe."

In the women's pair, Louisa Reeve and Olivia Whitlam were almost four seconds behind New Zealand's Emma-Jane Feathery and Rebecca Scown, while the USA and Australia came through the other semi-final and will push them for medals.

But Whitlam said: "Nobody's unbeatable, ever. That was a very contained race. It was a bit tight for the first 1,000m but we kept calm and followed our race plan."

Friday sees semi-finals for the women's lightweight double of Hester Goodsell and Sophie Hosking - Great Britain's best bet for a gold medal - and the lightweight men's double of Paul Mattick and Rob Williams.

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